1. Field of the Invention
The present invention relates to novel polyacetal compounds which are useful as surfactants. More specifically, individual blocks of polymers and copolymers of alkylene oxides are reacted with various vinyl ether compounds forming acetal terminated blocks. These blocks are then subjected to a transacetalization reaction which results in a coupling of the individual blocks through acetal linkages into multi-block copolymers.
2. Prior Art
Surface active non-ionic acetals of monoethers of mono and polyalkylene glycols are known in the art. As taught in U.S. Pat. No. 3,244,753 these products which are produced by reacting monoethers of polyalkylene glycols with vinyl ethers in the presence of an acid catalyst are stable to degradation and discoloration in aqueous alkali. This patent covers a process for capping polyalkylene glycols by reaction with vinyl ethers. It does not teach the coupling of hydrophobic and hydrophilic blocks through an acetal interchange.
U.S. Pat. No. 2,905,719 teaches the preparation of surfactants by reacting vinyl ethers containing 8 to 18 carbon atoms with ethoxylated alcohols. There is no teaching of linking polyoxyethylene and polyoxypropylene groups by using low molecular weight vinyl ethers. Neither is there a teaching of an acetal interchange reaction.
None of the prior art teaches the preparation of the particular surface active compounds of this invention nor of the process employed for the preparation of these compounds.